Mewtwo will be available as paid DLC in the future
Players who register both Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U on Club Nintendo before Jan. 20, 2015 will be able to obtain Mewtwo for both versions of SSB4, as well as two exclusive CDs with the music from both versions of the game.
Players who register both games between Jan. 20, 2015 and March 31, 2015 will still be able to receive Mewtwo for both versions of SSB4, but not the soundtrack CDs.
Players who qualify for Mewtwo will receive download codes for it in Northern Hemisphere spring 2015.
For the players who don't qualify for the promotion, Mewtwo will be released as paid DLC in the future.